G Hartzell | PubMed Health

PubMed1994

DNA sequence confidence estimation.

A significant bottleneck in the current DNA sequencing process is the manual editing of trace data generated by automated DNA sequencers. This step is used to correct base calls and to associate to each base call a confidence level. The confidence levels are used in the assembly process to determine overlaps and to resolve discrepancies in determining the consensus sequence. This single step may cost as much as 4 to 8 cents per finished base. We report an approach to automated trace editing using classification trees to detect and exploit context-based patterns in trace peak heights. Local base composition and nearby peak heights account for 80% of the variations in peak heights. Classification algorithms were developed to identify 37% of automated base calls that differ from the consensus sequence. With these algorithms, 12% of the base calls had confidence levels less than 90%.

Algorithms↗

PubMed1994

Laparoscopic versus conventional appendectomy.

BACKGROUND: The results of recent series suggest remarkable advantages of laparoscopic appendectomy over the conventional open appendectomy. To determine if clear advantages could be established, the charts of all patients admitted to our institution with a presumptive diagnosis of acute appendicitis and subsequent appendectomy were retrospectively reviewed. STUDY DESIGN: From January 1990 through June 1992, there were 300 conventional open appendectomies and 66 laparoscopic appendectomies performed. Data from both groups were compared with respect to anesthesia time, operative time, postoperative morbidity, postoperative pain, time to regular diet, hospitalization period, cost, and return to normal activities. RESULTS: There were no significant differences between the laparoscopic and open appendectomy groups with respect to operative complications, postoperative morbidity, pain medication requirements, and time to regular diet. There were significantly longer anesthesia times, operative times, and operating room costs in the laparoscopic group. For complicated appendicitis, the laparoscopic technique resulted in infectious complications that required readmission in 45.5 percent of the patients. CONCLUSIONS: Laparoscopic appendectomy is a safe alternative to conventional open appendectomy for simple acute appendicitis. However, laparoscopic appendectomy is not superior to the conventional method with regard to operative time, postoperative morbidity, pain medication requirements, time to regular diet, length of stay, cost, or return to normal activity. Laparoscopic appendectomy may be contraindicated in complicated appendicitis (gangrene, perforated with abscess, or peritonitis) due to an increased rate of infectious complications requiring readmission.

Acute Disease↗